Surface maintenance or condition machines—such as extractors—that use a cleaning liquid to clean a carpet, upholstery, or like surfaces are well known in the art. A conventional extractor generally includes a cleaning liquid delivery system including a container for holding the cleaning liquid, a rotating brush or a revolving scrubber for scrubbing the surface to be cleaned, and a gravity feed or pump for delivering the cleaning liquid to the surface. The conventional extractor also includes a cleaning liquid recovery system having a recovery nozzle, a suction generating device (such as a motor driven fan), and a dirty cleaning liquid recovery tank. Such extractors are more effective than typical vacuum cleaners due to their ability to loosen ground in dirt by the action of the rotating brush or revolving scrubber in conjunction with application of the cleaning liquid.
Known surface maintenance or condition machines suffer from various drawbacks. For example, many extractors leave excess amounts of cleaning liquid on the surface being cleaned, which must then be dried for an undesirable length of time. Excessive surface wetting may promote the growth of fungus and/or bacteria on or within the surface, especially when the surface is carpet. Additionally, over-wetting may cause surface stains to appear or reappear on the surface; this might occur, for example, as underlying soil or stains migrate upward through carpet until visible on the carpet surface. Some surface maintenance or condition machines also provide an uneven distribution of fluid across the surface to be cleaned, resulting in uneven cleaning of the surface and, in some cases, streaks on the surface.
Additionally, many surface maintenance or conditioning machines use pumps or spray jets to convey cleaning liquid from a cleaning liquid storage tank either to the surface itself or to a scrub brush or pad used to agitate and clean the surface. Such devices increase both the purchase cost and the complexity of the extractors in which they are used, require increased maintenance, and introduce additional failure modes.
Accordingly, there is a need for a cleaning liquid distribution system for use in surface maintenance or conditioning machines that evenly distributes an appropriate amount of cleaning fluid in an efficient, cost-effective, and low-maintenance manner.